排序方式: 共有46条查询结果,搜索用时 15 毫秒
21.
22.
D. A. Bountin Yu. V. Gromyko S. V. Kirilovskiy A. A. Maslov T. V. Poplavskaya 《Thermophysics and Aeromechanics》2018,25(4):483-496
In the present paper, we report on the results of a combined experimetal and numerical study of the laminar-turbulent transition at Mach number 5.95 in the boundary layers of 7-deg cones with a small nose-tip bluntness radius (down to 1.5 mm). The tip temperature of the model was varied in the range from 90 to 440 K. It was confirmed that the small nose-tip bluntness substantially shifts the position of the transition in downstream direction. This effect was also retained in testing the models with local heating/cooling of the cone tip. It is shown that for the experimental conditions implemented in the Transit-M wind tunnel, ITAM SB RAS, the local heating of blunt cone tips exerts almost no influence on the position of the transition. The local cooling of the cone tip with R = 1.5 mm leads to a shift of the transition position in upstream direction. 相似文献
23.
Doz. Dr. Gregor Ondrejovič Milan Melník Darina Makáňová Ján Gažo 《Monatshefte für Chemie / Chemical Monthly》1977,108(5):1047-1053
Cu(OPph
3)2Cl2 exists in yellow - and orange -isomeric forms. -Cu(OPph
3)2Cl2 was prepared by thermal decomposition of Cu(OPph
3)4Cl2·2 H2O and by reaction of CuCl2 with OPph
3 in acetone—ethanol mixture at higher temperature. The results of magnetic measurements, electronic andESR spectra show that the structure of -isomer differs from the known structure of the -isomer by a different degree of distortion of the coordination tetrahedron. -Cu(OPph
3)2Cl2 is thermodynamically more stable then -Cu(OPph
3)2Cl2.
Mit 3 Abbildungen 相似文献
Mit 3 Abbildungen 相似文献
24.
A new synthesis of attenol A is described. Key features of this work include a crucial silicon tether-aided coupling metathesis step and the use of iodoetherification as an efficient protection method for 1,5-ene-ols. [reaction: see text] 相似文献
25.
Yu.B. Vassiliev V.S. Bagotzky V.A. Gromyko 《Journal of Electroanalytical Chemistry》1984,178(2):247-269
Oxidation and reduction of platinum electrodes have been investigated in the potential range up to 3.0 V in acid, alkaline and phosphate buffer solutions with pH from 0 to 14. It is shown that oxygen adsorption and absorption on platinum are usually superimposed, but they may be artificially separated using a strong dependence of the second process upon platinum pretreatment and potential sweep rate. The dependence of oxygen surface coverage on potential has several characteristic regions, each corresponding to the formation of a definite surface oxycompound. 相似文献
26.
Ivanova Anastasiya Dvurechensky Pavel Vorontsova Evgeniya Pasechnyuk Dmitry Gasnikov Alexander Dvinskikh Darina Tyurin Alexander 《Journal of Optimization Theory and Applications》2022,193(1):462-490
Journal of Optimization Theory and Applications - Many convex optimization problems have structured objective functions written as a sum of functions with different oracle types (e.g., full... 相似文献
27.
D. A. Bountin Yu. V. Gromyko A. A. Maslov P. A. Polivanov A. A. Sidorenko 《Thermophysics and Aeromechanics》2015,22(6):767-770
As a rule, aerodynamic studies at hypersonic flow velocities are carried out in short-duration wind-tunnel facilities. For such facilities, optical diagnostic methods are most preferable. In the present study, we give for the first time a comparison of two methods for determining the end of laminar-turbulent transition: from the distribution of heat fluxes and from schlieren visualization data for the boundary-layer flow. Parametric data on the position of the transition are obtained. These data can be used in the future as reference ones while calibrating semi-empirical calculation models for the transition. 相似文献
28.
Jan Bures Ilja Tacheci Jaroslav Kvetina Vera Radochova Lukas Prchal Darina Kohoutova Martin Valis Martin Novak Rafael Dolezal Marcela Kopacova Stanislav Rejchrt Vit Sestak Veronika Knoblochova Eva Peterova Jana Zdarova Karasova 《Molecules (Basel, Switzerland)》2021,26(8)
Gastrointestinal side effects of donepezil, including dyspepsia, nausea, vomiting or diarrhea, occur in 20–30% of patients. The pathogenesis of these dysmotility associated disorders has not been fully clarified yet. Pharmacokinetic parameters of donepezil and its active metabolite 6-O-desmethyldonepezil were investigated in experimental pigs with and without small intestinal injury induced by dextran sodium sulfate (DSS). Morphological features of this injury were evaluated by a video capsule endoscopy. The effect of a single and repeated doses of donepezil on gastric myoelectric activity was assessed. Both DSS-induced small intestinal injury and prolonged small intestinal transit time caused higher plasma concentrations of donepezil in experimental pigs. This has an important implication for clinical practice in humans, with a need to reduce doses of the drug if an underlying gastrointestinal disease is present. Donepezil had an undesirable impact on porcine myoelectric activity. This effect was further aggravated by DSS-induced small intestinal injury. These findings can explain donepezil-associated dyspepsia in humans. 相似文献
29.
Katarzyna Wrzosek Michal Gramblička Darina Tóthová Monika Antošová Milan Polakovič 《Chemical Papers》2010,64(4):461-468
The influence of ionic strength on the adsorption capacity of seven commercial adsorbents used in downstream processing of
monoclonal antibodies was examined. Affinity (MabSelect, Poros 50A High Capacity, ProSep-vA High Capacity), hydrophobic charge-induction
(MEP HyperCel), and cation exchange adsorbents (FractoGel EMD SE Hicap (M), SP Sepharose Fast Flow, Ceramic HyperD F) were
used to study the adsorption of polyclonal human immunoglobulin G at optimal pH values. The ionic strength, adjusted by sodium
chloride concentrations in the range of 0–225 mM, strongly decreased the adsorption capacity of the cation exchangers. Equilibrium
data were described in the form of the dependence of the ratio of protein concentrations in the solid and liquid phases on
the total concentration of cation counter ions. They were successfully fitted and interpreted through a stoichiometric ion-exchange
model. 相似文献
30.
P. A. Polivanov Yu. V. Gromyko D. A. Bountin A. A. Maslov A. A. Sidorenko 《Thermophysics and Aeromechanics》2017,24(6):941-944
As a rule, experimental studies at hypersonic Mach numbers are carried out in short-duration wind tunnels. Under such conditions, data on boundary-layer pulsations are primarily measured by surface pressure sensors. There are many factors affecting the level of pulsations at model walls; that is why the cross-correlation analysis is often invoked to analyze the development of wave packets in boundary layer. However, the standard correlation analysis very often fails in providing the possibility to trace the evolution of wave packets. In the present publication, we propose a new method for obtaining cross-correlation data based on the wavelet transform. 相似文献